In food, cosmetics and pharmaceutical industries there is a major need for low-cost, natural emulsifiers/stabilizers.
Million tons of grape pomace (skins, seeds and stalks) are being produced every year by the wine industry. Only in the countries of the European Union the annual production exceeds 40 million tons (Bettini, 2014). That leads to massive amounts of grape wastes, which, if not directly disposed of, they are typically being used for the production of animal feed or of compost. Until today, the best effort for the utilization of grape by-products is the reclaim of polyphenols, whose benefits in human health are widely documented (Shrikhande, 2000; Ruberto et al., 2007). The point of interest turns to the possibility of recovering food-grade materials of high added value such as emulsifying and stabilizing agents from the solid grape waste.
During processing of grape, including but not limited to the process of vinification, the cell walls of the grape rupture. These walls are reported to contain, among other substances, tannins, proteins, cellulose, and water-soluble polysaccharides (Varandas et al., 2004, Mendes, Prozil, Evtuguin & Lopes, 2013). A number of studies have reported that the water-soluble polysaccharides comprise of various monosacharides, like arabinose, fucose, galactose, glucose, mannose, rhamnose, xylose and uronic acids (Vidal, Williams, O'Neill & Pellerin, 2001; Doco, Williams, Pauly, O'Neill & Pellerin, 2003; Prozil, Evtuguin & Lopes, 2012; Mendes et al. 2013; Rondeau, Gambier, Jolibert & Brosse, 2013). The above materials that can be retrieved from grape by-products seems appropriate for use as food-grade hydrocolloids for applications such as emulsifiers or stabilizers of food products.